The EU referendum takes place on Thursday 23 June. Have you decided how you’re going to vote yet?
To help you make up your mind, we've rounded up the key points from the Remain and Leave campaigns.
The economy is a key battleground for both sides and much of the Leave campaign's argument focuses on the cash paid by the UK to the EU.
Leavers point to the amount sent by the UK to the EU - which amounts to £50m each day - arguing that this could be better spent on British priorities such as the NHS.
Remain's economic campaign targets the effect of leaving the EU, with a number of experts predicting economic crisis should the UK go it alone.
Remain argues that the EU is the UK’s biggest trading partner. In 2014, exports to EU countries accounted for 44% of all UK exports. Remain says a tight bond is therefore vital for the UK economy.
Remain supporters also say the UK will become a less attractive home for foreign investment if it's not in the EU; and that without this investment London might lose its position as a financial capital.
The Leave campaign argues that, by removing EU regulations from the workplace, more jobs would be created in the UK.
By allying that with reduced levels of migration, Leavers say that UK residents would see wages pushed up.
The Remain campaign says Brexit could have a negative effect on millions of UK jobs. It says there are more than 3 million British jobs linked to trade with the EU and says more than a million of these could be lost if the UK decides to leave the EU.
Leave argues that if the UK were outside the EU, we could strike a free-trade agreement similar to the Swiss model. This would mean the UK enjoying free trade within the EU, but without as many of its regulations or laws.
The Leave position is that, because of the UK's existing agreements with the EU, this process should be fairly simple to do.
Remain has criticised the Swiss model as being an unrealistic aim. It took Switzerland six years to reach its first agreement with the EU, which was rejected by the Swiss and had to be reworked, taking several more years. This is far longer that Leavers predict.
Remain also argues that the agreements made would have to be regularly amended to keep them in line with EU laws. Therefore the influence of the EU would remain, but the decision-making rights of the UK would be taken away.
Even if the UK were to leave the EU, British businesses which operate in Europe would still be bound by EU regulations. Remain campaigners say that, by staying in the EU, we can have a say in how this single market operates, rather than simply complying with its regulations.
Border control, immigration and terrorism
Brexit campaigners say that leaving the EU will enable the UK to reduce immigration, reducing pressure on welfare and the health service. The Leave position is that migration could increase the UK population by as much as 5.2m by 2030. It's argued that this could increase demand on NHS A&E services by 57%.
Prominent Leaver Michael Gove has claimed that this population increase would leave the NHS having to “look after a new group of patients equivalent in size to four Birminghams”. Leave campaigners have also suggested that, by tightening UK borders, there is less of a risk of potential terrorists entering the country.
Remain has said that, by leaving the EU, Britain would lose the protection and surveillance of 27 member states. This implies that other member states will stop supplying the UK with information regarding national security. David Cameron has even been quoted that Islamic State “might be happy” if the UK were to leave the EU as security would be so diminished. Leave has dismissed this as scaremongering.
As for immigration, Remain has said that leaving the EU might not have much effect. The terms of any trade deal struck by the UK may mean EU migrants could still enter Britain fairly easily.
Remain's response the to Leave campaign's NHS argument is that the population increase that has been forecast is unlikely, and that the pressures placed on the NHS would be much smaller.
Leave argues that, by staying in the EU, the UK would have less power than big countries such as Germany and France. The UK currently has less than a 10% share of the vote within the EU. Leave says this limits the UK's ability to influence EU policy and that it could have more of an international influence outside the EU.
Leavers also say that the UK could retain influence within the EU because we would still be a contributor to NATO and retain links to other organisations such as G8 and G20. Furthermore, a Brexit would ensure that Britain would have its own seat at the World Trade Organisation. That's not the case at the moment, where it falls under the EU.
Barack Obama is among the people who believe the UK's global influence would be diminished should it leave the EU.
"What we do believe is that the United Kingdom would have less influence in Europe and as a consequence, less influence globally," said the US president.
"We rely heavily on the UK as a partner globally on a whole range of issues - we like you having more influence."
Remain campaigners have also suggested that leaving the EU could affect London's position as a financial capital, with multinational banks that currently have their European headquarters in London moving them to elsewhere in Europe.
Future generations and living standards
Leave campaigners have suggested each UK household could be around £1,000 better off each year outside the EU. It points to data that shows food bills being 17% more expensive "as a direct result of EU policies".
Data reported by The Guardian suggests that average house prices could cost £2,300 less by 2018 if we were outside the EU, potentially easing pressure on first-time buyers.
Nicky Morgan has said an exit from Europe would create a “lost generation” of young people, with uncertainty around the economy and job market.
Remain also argues that remaining in the EU gives young people in the UK opportunities to work, study and travel in the EU.
The Remain campaign believe that standards of living would be higher if UK remains within the EU, with flights to Europe and data roaming among the things that are cheaper. It's argued that imported food prices are likely to rise if the UK leaves.
National identity and sovereignty
Leave campaigners believe the EU is on its way to becoming a federal state, where the individual countries have to answer to a central power. Boris Johnson has said the EU is turning into a "superstate into which we would inevitably be dragged".
Core to the Leave campaign is the desire for the UK to make its own laws and forge its own relationships with other countries.
David Cameron has said that leaving the EU would give no more than "an illusion of sovereignty".
Interviewed on the BBC's Andrew Marr Show in February, the prime minister said: "Would you have power to help businesses not be discriminated against in Europe? No, you wouldn't. Would you have the power to insist European countries share with us their border information so we know what terrorists and criminals are doing in Europe? No, you wouldn't."
The Remain position is that it's essential to share sovereignty in order to have strength within Europe.
The referendum is on Thursday 23 June 2016. Are you registered to vote? If not, you can do it online on the government's Register To Vote page. You must register by 7 June 2016 in order to vote in the EU referendum.